Signaling events in workflow management systems

ABSTRACT

The present invention provides a computerized method for determining an addressee of a signaling request within a Workflow Management System or a computer system with comparable functionality (WFMS). Upon receiving a signaling request, which is providing a set of signal data elements, the current invention avoids the requirement that the signal data elements comprise any explicit specification of an addressee of said signaling request. To determine whether an event-activity of a process-instance being the instance of a process-model of a business-process is the potential addressee of the signaling request it is suggested to determine, whether the process-model comprises an event-identification-specification. This event-identification-specification according to the current invention is involving a subset of the signal data elements. Evaluating the event-identification-specification allows to indirectly decide if the event-activity is the addressee of the signaling request.

1. BACKGROUND OF THE INVENTION

1.1 Field of the Invention

The present invention relates to means and a method for improving therobustness and ease-of-use of Workflow-Management-Systems or a computersystem with comparable functionality (WEMS) related to the signaling ofevents.

1.2 Description and Disadvantages of Prior Art

A new area of technology with increasing importance is the domain ofWorkflow-Management-Systems (WFMS). WFMS support the modeling andexecution of business processes. Business processes executed within aWEMS environment control who will perform which piece of work of anetwork of pieces of work and which resources are exploited for thiswork. The individual pieces of work might be distributed across amultitude of different computer systems connected by some type ofnetwork.

The product “IBM MQSeries Workflow” (previously called IBM FlowMark)represents such a typical modern, sophisticated, and powerful workflowmanagement system. It supports the modeling of business processes as anetwork of activities. This network of activities, the process model, isconstructed as a directed, acyclic, weighted, colored graph. The nodesof the graph represent the activities, which are performed. The edges ofthe graph, the control connectors, describe the potential sequence ofexecution of the activities. Definition of the process graph is via IBMMQSeries Workflow's Flow Definition Language (FDL) or via the built-ingraphical editor.

The runtime component of the Workflow-Management-System uses saidprocess model as a template to create process instances. Each processinstance is associated with a set of values, typically called thecontext. Said values are either supplied by the requestor of the processinstance via the appropriate request or retrieved by programs thatimplement the various activities or are the result of the executionhistory of a certain process instance. The context is unique to acertain process instance. A particular important piece of informationwithin said context is the process instance identifier that uniquelyidentifies a process instance. It should be noted that typically processinstance identifiers are only unique within the set of process instancesthat are derived from a particular process model.

Particular important types of activities are event activities. An eventactivity provides the capability to have a process instance waitinguntil signaled. The signal, or in other words the event, may be createdwithin the WFMS but typically will have its source in the outside of theworkflow management system. Upon receiving said signal, the workflowmanagement system stores the supplied information as context information(in this case into the output container of the event activity) andcontinues navigation.

Signaling the event is done via an appropriate signal request to theworkflow management system. Said signal request may be created by aprogram exploiting the application-programming interface offered by theworkflow management system or by sending an appropriate workflowmanagement system defined message to the workflow management system thatcan typically carry such a signal request. Independently of howsignaling is done, the signaling request must contain the appropriateprocess instance identifier of the process instance in which the eventis waiting as well as the identification of the event. This informationis necessary so that the workflow management system can locate thecorrect process instance and the correct event within the process model.If the issuer of the signaling request does not know the eventidentification or even does not know the process instance identifier,the issuer must obtain this information. To facilitate this the workflowmanagement provides query capabilities that allow the issuer to querythe input container of the-event activity. It is the responsibility ofthe process modeler to make sure that the input container of the eventactivity contains the appropriate values from which the process instanceidentification can be derived.

This state-of-the-art approach has several deficiencies, in particularwhen an event is signaled by sending a message to the workflowmanagement system:

-   -   The signaler of the event must indicate to the workflow        management system that the request is for signaling an event;        that means the requester must follow the message structure        defined by the workflow management system. This structure        typically mandates to have certain indicators, such as the        command that the message represents, in certain places of the        message; for example the text string signal as the first field        of the message. This mandates that an existing message-oriented        signaler program must be adapted when the signal should now be        processed by a workflow management system; an approach that is        not always possible to implement. Another approach to overcome        this situation is the usage of a translation program that        translates the signaler's original message into the workflow        management specific message; an approach that increases not only        the complexity of the overall system (making maintenance and        system management much more complicated) but also decreases        performance for generating a signal.    -   The signaler must maintain the process instance identifier of        the target process instance. If this is not possible, the        signaler must obtain appropriate information (data in the input        container of the event) from the workflow management system.        This requires that the signaler already knows the name of the        event so that it can set up the appropriate query to the        workflow management system. This has the disadvantage that every        change made to the process model such as changing the name of        the event requires re-programming on the signaler's part (such        as adapting the new name of the event).    -   The signaler must know the name (according to the nomenclature        of the WEMS) of the event even if it knows the process instance        identifier. Knowing the name includes knowing to some extent the        structure of the process model; for example the process model        could use the same name multiple times within the same process        model, a situation that can easily arise when one synthesizes        more, complex process models from simpler process models.

The above listed deficiencies make it obvious that the current state ofthe art enforces a tight coupling between the signaler of an event andthe workflow management system manifested by the information that thesignaler must maintain about information that the workflow managementsystem maintains. This situation is quite undesirable for the reasonsoutlined above. It should be possible to specify in the workflowmanagement system all information necessary to process an almostarbitrary message for signaling an event. Further it should be possiblefor an arbitrary signaling of events to send signaling events to a WFMSwithout said signal being adapted to WEMS requirements. The arbitrarysignaler should allowed to be unaware of the concrete nature of theconsumer (that is the addressee) of the signaling requests. Then it ispossible that the signaler can be developed independently from theconsumer of the signaling request.

The weakness of the state-of-the-art approaches with respect to thisproblem area becomes even more distinct if one thinks of typicalInternet scenarios commonly summarized by terms like C2B(Consumer-to-Business) or B2B (Business-to-Consumer) business processes.In these scenarios, it is obvious that the tight coupling of signaler tothe workflow management system is not desirable at all.

1.2 Objective of the Invention

The invention is based on the objective to eliminate the need for eventsignalers to maintain information that is needed to locate theappropriate event in the appropriate process instance waiting fornotification of said event.

2. SUMMARY AND ADVANTAGES OF THE INVENTION

The objectives of the invention are solved by the independent claims.Further advantageous arrangements and embodiments of the invention areset forth in the respective subclaims.

The present invention provides a computerized method for determining anaddressee of a signaling request within a Workflow Management System ora computer system with comparable functionality (WFMS).

Upon receiving a signaling request, which is providing a set of signaldata elements, the current invention avoids the requirement that thesignal data elements comprise any explicit specification of an addresseeof said signaling request.

To determine whether a particular event-activity of a process-instancebeing the instance of a process-model of a business-process is thepotential addressee of the signaling request it is suggested todetermine, whether the process-model comprises anevent-identification-specification. Thisevent-identification-specification according to the current inventioninvolves a subset of the signal data elements. Evaluating theevent-identification-specification allows to indirectly decide if theevent-activity is the addressee of the signaling request.

The suggested teaching avoids all of above-mentioned deficiencies.Relieving the signaler of a signaling request from specifying a certainaddressee based on the suggested approach offers the further advantagethat multiple addressees might exist for a single signaling messaging.

3. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a process model represented by a processgraph.

FIG. 2 illustrates the implementation of signatures of activities asinput and out containers and the movement of data from one activity toanother activity via data connectors

FIG. 3 illustrates the structure of an event activity that whenactivated waits for a message to be processed.

FIG. 4 illustrates the definition of a message signaling an event usingan XML schema definition for describing the contents of the message.

FIG. 5 visualizes the details of the necessary specifications using theFlow Definition Language of MQSeries Workflow.

FIG. 6 illustrates an alternate method of determining the structure of amessage that signals an event.

FIG. 7 illustrates an alternate method of identifying the event that isthe target of a signaling message.

4. DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings and specification there has been set forth a preferredembodiment of the invention and, although specific terms are used, thedescription thus given uses terminology in a generic and descriptivesense only and not for purposes of limitation. It will, however, beevident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention asset forth in the appended claims.

The present invention can be realized in hardware, software, or acombination of hardware and software. Any kind of computer system—orother apparatus adapted for carrying out the methods described herein—issuited. A typical combination of hardware and software could be ageneral-purpose computer system with a computer program that, when beingloaded and executed, controls the computer system such that it carriesout the methods described herein. The present invention can also beembedded in a computer program product, which comprises all the featuresenabling the implementation of the methods described herein, andwhich—when being loaded in a computer system—is able to carry out thesemethods.

Computer program means or computer program in the present context meanany expression, in any language, code or notation, of a set ofinstructions intended to cause a system having an information processingcapability to perform a particular function either directly or aftereither or both of the following a) conversion to another language, codeor notation; b) reproduction in a different material form.

The current invention is illustrated based on IBM's “MQSeries Workflow”workflow management system. Of course any other WFMS could be usedinstead. Furthermore the current teaching applies also to any other typeof system, which offers WFMS functionalities not as a separate WFMS butwithin some other type of system.

According to the current teaching it is advantageous if the WFMS engineis the processing entity to determine the addressee(s) of any signalingrequest based on the data elements provided by the signaler. But ofcourse, the current invention can be applied in other scenarios whereinthe processing entity of the request for signaling an event is not theWFMS engine itself some other entity.

4.1 Introduction

The following is a short outline on the basic concepts of a workflowmanagement system based on IBM's “MQSeries Workflow” WFMS:

From an enterprise point of view the management of business processes isbecoming increasingly important: business processes or process for shortcontrol which piece of work will be performed by whom and whichresources are exploited for this work, i.e. a business process describeshow an enterprise will achieve its business goals. A WFMS may supportboth, the modeling of business processes and their execution.

Modeling of a business process as a syntactical unit in a way that isdirectly supported by a software system is extremely desirable.Moreover, the software system can also work as an interpreter basicallygetting as input such a model: The model, called a process model orworkflow model, can then be instantiated and the individual sequence ofwork steps depending on the context of the instantiation of the modelcan be determined. Such a model of a business process can be perceivedas a template for a class of similar processes performed within anenterprise; it is a schema describing all possible execution variants ofa particular kind of business process. An instance of such a model andits interpretation represents an individual process, i.e. a concrete,context dependent execution of a variant prescribed by the model. A WEMSfacilitates the management of business processes. It provides a means todescribe models of business processes (buildtime) and it drives businessprocesses based on an associated model (runtime). The meta model ofIBM's WEMS MQSeries Workflow, i.e. the syntactical elements provided fordescribing business process models, and the meaning and interpretationof these syntactical elements, is described next.

A process model is a complete representation of a process, comprising aprocess diagram and the settings that define the logic behind thecomponents of the diagram. Important components of an MQSeries Workflowprocess model are:

-   -   Processes    -   Activities    -   Blocks    -   Control Flows    -   Connectors    -   Data Containers    -   Data Structures    -   Conditions    -   Programs    -   Staff

Not all of these elements will be described below.

Activities are the fundamental elements of the meta model. An activityrepresents a business action that is from a certain perspective asemantic entity of its own.

An MQSeries Workflow process model consists of the following types ofactivities:

Program activity: Has a program assigned to perform the activity. Theprogram is invoked when the activity is started. In a fully automatedworkflow, the program performs the activity without human intervention.Otherwise, the user must start the activity by selecting it from aruntime work list. Output from the program can be used in the exitcondition for the program activity and for the transition conditions toother activities.

-   -   Process activity: Has a (sub-)process assigned to perform the        activity. The process is invoked when the activity is started. A        process activity represents a way to reuse a set of activities        that are common to different processes. Output from the process,        can be used in the exit condition for the process activity and        for the transition conditions to other activities.

The flow of control, i.e. the control flow through a running processdetermines the sequence in which activities are executed. The MQSeriesWorkflow workflow manager navigates a path through the process that isdetermined by the evaluation to TRUE of start conditions, exitconditions, and transition conditions.

Connectors link activities in a process model. Using connectors, onedefines the sequence of activities and the transmission of data betweenactivities. Since activities might not be executed arbitrarily they arebound together via control connectors. A control connector might beperceived as a directed edge between two activities; the activity at theconnector's end point cannot start before the activity at the startpoint of the connector has finished (successfully). Control connectorsmodel thus the potential flow of control within a business processmodel. Default connectors specify where control should flow when thetransition condition of no other control connector leaving an activityevaluates to TRUE. Default connectors enable the workflow model to copewith exceptional events. Data connectors specify the flow of data in aworkflow model. A data connector originates from an activity or a block,and has an activity or a block as its target. One can specify thatoutput data is to go to one target or to multiple targets. A target canhave more than one incoming data connector.

Process definition includes modeling of activities, control connectorsbetween the activities, input/output container, and data connectors. Aprocess is represented as a directed acyclic graph with the activitiesas nodes and the control/data connectors as the edges of the graph. Thegraph is manipulated via a built-in graphic editor. The data containersare specified as named data structures. These data structures themselvesare specified via the DataStructureDefinition facility. Programactivities are implemented through programs. The programs are registeredvia the Program Definition facility. Blocks contain the same constructsas processes, such as activities, control connectors etc. They arehowever not named and have their own exit condition. If the exitcondition is not met, the block is started again. The block thusimplements a Do Until construct. Process activities are implemented asprocesses. These subprocesses are defined separately as regular, namedprocesses with all its usual properties. Process activities offer greatflexibility for process definition. It not only allows to construct aprocess through permanent refinement of activities into program andprocess activities (top-down), but also to build a process out of a setof existing processes (bottom-up).

All programs, which implement program activities, are defined via theProgram Registration Facility. Registered for each program is the nameof the program, its location, and the invocation string. The invocationstring consists of the program name and the command string passed to theprogram.

As an example of such a process model FIG. 1 shows schematically thestructure of such a process graph. Activities (A1 up to A5) arerepresented as named circles; the name typically describes the purposeof the activity. Activities come in various flavors to address thedifferent tasks that may need to be performed. They may have differentactivity implementations to meet these diverse needs. Program activitiesare performed by an assigned program, process activities like forinstance 100 are performed by another process 101, and blocks like forinstance 102 implement a macro 103 with a built-in do-until loop.Control connectors p12, p13, p24, p35, p45 are represented as arrows;the head of the arrow describes the direction in which the flow ofcontrol is moving through the process. The activity where the controlconnector starts is called the source activity; where it ends is calledthe target activity. When more than one control connector leaves anactivity, this indicates potentially parallel work.

4.2 Containers and Data Connectors

FIG. 2 shows the two activities A 200 and B 210, Which may be part of amore complex process model. Both activities A 200 and B 210 have aninput container 220, 240 associated with them; activity A 200 has alsoan output container 230 associated with. In a fundamental alterationaccording to the current invention the input and output container of anactivity can be viewed conceptually as the signature of the activity.The activity obtains data necessary for its execution from the inputcontainer and writes data that it produces and that is needed for otheractivities into the output container. As with signatures, the containersof an activity are only available to the activity; that means they areonly available locally. For example, the input container 220 and theoutput container 230 are only available to the associated activity A200. Thus, if activity B 210 needs data, for example, from the outputcontainer 230 of the activity A 200, this data must be copied from theoutput container 230 of the activity A 200 to the input container 240 ofthe activity B 210.

For the purpose of copying data from one of the activities to anotheractivity, a data connector 260 is provided which is depicted in FIG. 2as a dashed arrow. The data connector 260 of FIG. 2 indicates that allor parts of the output container 230 of the activity A 200 has to becopied to the input container 240 of the activity B 210.

The output container of one activity and the input container of anotheractivity, however, generally have different data structures, for examplecontaining different data fields. Therefore, a container map 250 isprovided in FIG. 2 which defines which data fields of the outputcontainer 230 of the activity A 200 are copied into which data fields ofthe input container 240 of the activity B 210. The container map 250also specifies if a transformation of the data has to be performed bythe workflow management system before the data is copied e.g. into theinput container 240 of the activity B 210.

4.3 Event Activities

Event activities are another type of activities that workflow managementsystems support. They provide the capability to have a process instancewait until the event is signaled for instance from outside the workflowmanagement system upon. Upon receiving the signal, the workflowmanagement system processes the request and continues navigation. Anevent activity has most of the properties program and processactivities. Is associated with an input and an output container. It canbe source and the target of control connectors as well as the source andtarget of data connectors. It has a start condition, and a deadline canbe specified for it.

FIG. 3 illustrates this schematically showing portion 301 of some morecomplex process model. An event activity 300 goes into the waiting stateas soon the control connector 360 enters the event activity. If inrealization of a process model the event activity has no incomingcontrol connector, the event activity goes into the waiting state assoon as the process instance is created. The event activity remains inthis state until the event is signaled. Some client 310 is issuing anappropriate request 350 to the workflow management system signaling theevent the event activity 300 is waiting for. This request must (1)identify the appropriate event (2) in the appropriate process instanceas addressee. Additionally the event signal may supply data that isstored in the output container 320, so that information provided by theevent signaler can be made available to the process instance. When theevent is signaled correctly, navigation continues. Further details onevent activities can be found in Leymann/Roller, Production Workflow:Concepts and Techniques, Prentice Hall, N.J. ISBN and in U.S. Pat. No.6,065,009 Events as Activities in Process Models of Workflow ManagementSystems.

4.4 Defining Messages via XML

FIG. 4 shows the definition of a message via XML Schema Definition (seehttp://www.w3.org for details about XML and XML schema). The purpose ofthe message is to signal an event to the event activity defined in FIG.5. The keyword complexType 400 starts the definition of a user-definedXML structure. The name of the structure is SignalMessage 410. Thestructure consists of a set of elements 420, with an element name 430and a data type 440 of said element.

4.5 Processing the Signaling of an Event

FIG. 5 illustrates how the present invention can beimplemented/specified using the Flow Definition Language (FDL) ofMQSeries Workflow, a state-of-the-art Workflow-Management-System sold bythe applicant. FDL is used as an example only; any other way ofspecifying the signaling of events can be used. The underlying metamodel is also for illustration only; other meta models can be usedinstead.

The important teaching of the current invention is to provide atechnology allowing an arbitrary signaler of an event to be completelyunaware of the addressee of a signaling request; that means the concreteprocess instance waiting for said event. This releases the signaler frommaintaining the process instance identifier of the awaiting concreteprocess instance and from maintaining the identifier of event activitywithin the corresponding process model.

Is a fundamental observation of the current invention that the dataelements or a subset of the data elements provided by the signalerwithin the signaling request can be exploited by the WFMS itself touniquely identify the concrete process instance (or process instances)and/or the concrete event activity (or event activities) being theaddressee(s) of the event.

To enable the WFMS to perform this identification task it is suggestedto enhance the process model comprising an event activity withspecifications defining that set of (one or multiple) data elementsprovided by the signaling request to be used to identify a certainprocess instance of said process model and said event activity asaddressee. Once the signaling request is received by the WFMS, the WFMSknowing the process model would exploit these predefined eventidentification specifications and the concrete data elements providedwith the signaling request to determine the concrete addressee of theevent.

The example illustrates the definition of an event activity thatexploits the present invention.

The DATASTRUCTURE definition 500 identifies a data structure with thename SignalMessage 501. The data structure references (via the XMLkeyword) 502 an XML schema SignalMessage 503 (this is the XML schemadefined in FIG. 4). This data structure defines the structure of themessage that is accepted a signal that posts the event activity 520.

The DATASTRUCTURE definition 510 identifies a data structure with thename EventOutput. The data structure contains a field AmountOffered oftype INTEGER 512. This data structure is used for the output containerof the event activity 520; the field AmountOffered is intended as thetarget for the appropriate field supplied in the signaling message.

The event activity is defined via the EVENT_ACTIVITY keyword 520; thename of the event activity is ReceiveOffer 522. The output container ofthe event activity is defined via the OUTPUT keyword, which identifiesthe data structure EventOutput 524 as the structure for the outputcontainer.

The keyword SIGNAL 540 identifies all properties associated withsignaling the event; in specific the event identification specificationsproposed by the current invention are comprised within this section.Within the current example it identifies that the data structureSignalMessage 526 represents the structure of the message signaling theevent.

The keyword MESSAGE_IDENTIFICATION 536 is used to indicate to theworkflow management system how the structure of the message should bedetermined; that is defining the layout of the message. The parameterXML_SCHEMA 528 indicates that the message provided XML schema nameshould be used (this is typical for XML messages as it is desireable tobe able to use an XML parser for parsing the message). Other possibleparameter values of the MESSAGE_IDENTIFICATION parameter will bediscussed below. If the signaling message is of the specified XMLschema, the workflow management system takes this message as a potentialsignaling message for this ReceiveOffer activity. That means, if thesignaling message is of XML schema SignalMessage, the signaling messageis a candidate for a signaling message for the event activityReceiveOffer 522.

The keyword PROCESS_INSTANCE 542 identifies the field(s) in thesignaling message that should be used to identify the process instance.In the example, the field ContractId 530 from the XML message is used.In general the process instance can be identified by any arbitrarycomplex Boolean expression involving values of data elements within thesignaling message and data elements from the process instance's context.

The keyword TARGET_IDENTIFICATION 544 is used to define an expression532 that when it evaluates to true, the signaling message is targetedtowards the event activity. Thus this keyword allows identifying theconcrete activity within the process model the event is to be signaledto by the WFMS. The expression is constructed by using one or morefields in the signaling message. In the example, the signaling messageis targeted for this activity, if the field ActionId in the signalingmessage contains the text string ReceiveOffer.

The MAP keyword 546 provides for the capability of mapping fields fromthe signaling message to the activity output container. In the example,it copies the field AmountOffered from the signaling message to theoutput container. Other possibilities are the copying of fields of thesignaling message to a global/key container (see Leymann/Roller:Production Workflow: Concepts and Techniques, Prentice Hall, 2000 fordetails).

Another possibility to identify the structure of a signaling message isillustrated in FIG. 6. It defines an expression, that when it evaluatesto true, the signaling message has the structure specified as thesignaling message structure. That means when the field messageId 610contains the value 512, the signaling message has the structure definedfor the signaling message and therefore is a candidate for a signalingmessage for the event activity ReceiveOffer.

FIG. 6 proposes a solution to a further problem. In certain environmentspotential addressees are unique only within said certain domains.Examples for such a situation are process instance identifiers, whichare unique only within that set of process instances, which are derivedfrom a common process model.

To cope with such situations it is suggested that the eventidentification specification comprises specifications, which, whenevaluated, allow to limit the scope of potential addressees to processinstances of a common process model. The specific embodiment 620 in FIG.6 allows to construe from one or more data elements of the signalingmessage (in this example the parameter businessProcessID—refer to FIG.4) an identifier of a process model. As a consequence only processinstances which are instantiated from process models with this construedidentifier are viewed as potential addressees; of course the otherspecifications within event identification specifications will furthernarrow and identify the concrete addressee(s).

An event within a process instance is uniquely identified via anactivity instance identifier. Thus an alternate approach exists for thespecification of the target of a signaling message. Said specificationis an alternate specification for the combination of PROCESS_INSTANCEand TARGET_IDENTIFICATION specification. FIG. 7 illustrates how such aspecification could look like. The keyword ACTIVITY_IDENTIFICATION 710identifies one or more fields within the signaling message to construe(even by a more complex expression) the identifier of an event activitybeing the addressee of the signaled event. In the current example, thefield EventId 720, which is part of the signaling message, is useddirectly to construe the event activity identifier representing saidaddressee.

At runtime the above specifications are used by the WEMS in thefollowing manner:

First the WFMS determines the structure of the signaling message. Thisrequires inspecting all MESSAGE_DEFINITIONs for all event activities inall process models. If the structure of the signaling message cannot bedetermined, the WEMS assumes that the message is not an event-signalingmessage and takes other necessary actions.

Second, the WFMS determines the process instance that is the target ofthe signaling message.

Third, the WFMS determines the activity instance within said processinstance that is the target of the signaling message.

Fourth, the WFMS copies fields from the signaling message to the contextof the process instance.

1. A computerized method for determining an addressee of a signalingrequest within a Workflow Management System or a computer system withcomparable functionality (WFMS), said WFSM administrating aprocess-instance being the instance of a process-model of abusiness-process: and said method being further characterized by saidprocess-model comprising at least one event-activity, and in afirst-step said WFMS receiving a signaling request, said signalingrequest providing a set of signal data elements; and said signal dataelements not comprising any explicit specification identifying saidprocess-instance or said event-activity as addressee of said signalingrequest; and in a second-step said WFMS determining whether saidprocess-model comprises an event-identification-specification involvinga subset of said signal data elements: and, in the affirmative case,evaluating said event-identification-specification to indirectly decideif said event-activity is an addressee of said signaling request; and,in a third-step said WFMS providing said signaling request to saidevent-activity as addressee.
 2. A computerized method for determining anaddressee of a signaling request according to claim 1, wherein saidevent-identification-specification comprises a first-specification,which by evaluating is deciding if said process-instance is saidaddressee of said signaling request.
 3. A computerized method fordetermining an addressee of a signaling request according to claim 2,wherein said event-identification-specification comprises asecond-specification, which by evaluating is deciding if saidevent-activity of said process-instance is said addressee of saidsignaling request.
 4. A computerized method for determining an addresseeof a signaling request according to claim 3, wherein at least one of thefirst and second specifications comprises a Boolean-predicate furtherinvolving data elements of a context of said process-instance.
 5. Acomputerized method for determining an addressee of a signaling requestaccording to claim 3, wherein said second-specification is construingfrom said subset of said signal data elements a first identifier to becompared to a second identifier identifying said event-activity fordeciding if said event-activity of said process-instance is saidaddressee of said signaling request.
 6. A computerized method fordetermining an addressee of a signaling request according to claim 2,wherein said event-identification-specification comprises afourth-specification, which by evaluating is limiting the scope ofpotential addressees to process instances of said process model.
 7. Acomputerized method for determining an addressee of a signaling requestaccording to claim 1, wherein said event-identification-specificationcomprises a third-specification to decide based on the type of saidsignaling request if said process-instance is said addressee of saidsignaling request.